Use system specs instead of feature specs

We get rid of database cleaner, and JavaScript tests are faster because
between tests we now rollback transactions instead of truncating the
database.

spec/system/admin_spec.rb

@@ -0,0 +1,100 @@
+require "rails_helper"
+
+describe "Admin" do
+  let(:user) { create(:user) }
+  let(:administrator) do
+    create(:administrator, user: user)
+    user
+  end
+
+  scenario "Access as regular user is not authorized" do
+    login_as(user)
+    visit admin_root_path
+
+    expect(page).not_to have_current_path(admin_root_path)
+    expect(page).to have_current_path(root_path)
+    expect(page).to have_content "You do not have permission to access this page"
+  end
+
+  scenario "Access as moderator is not authorized" do
+    create(:moderator, user: user)
+    login_as(user)
+    visit admin_root_path
+
+    expect(page).not_to have_current_path(admin_root_path)
+    expect(page).to have_current_path(root_path)
+    expect(page).to have_content "You do not have permission to access this page"
+  end
+
+  scenario "Access as valuator is not authorized" do
+    create(:valuator, user: user)
+    login_as(user)
+    visit admin_root_path
+
+    expect(page).not_to have_current_path(admin_root_path)
+    expect(page).to have_current_path(root_path)
+    expect(page).to have_content "You do not have permission to access this page"
+  end
+
+  scenario "Access as manager is not authorized" do
+    create(:manager, user: user)
+    login_as(user)
+    visit admin_root_path
+
+    expect(page).not_to have_current_path(admin_root_path)
+    expect(page).to have_current_path(root_path)
+    expect(page).to have_content "You do not have permission to access this page"
+  end
+
+  scenario "Access as poll officer is not authorized" do
+    login_as(create(:poll_officer).user)
+    visit admin_root_path
+
+    expect(page).not_to have_current_path(admin_root_path)
+    expect(page).to have_current_path(root_path)
+    expect(page).to have_content "You do not have permission to access this page"
+  end
+
+  scenario "Access as administrator is authorized" do
+    login_as(administrator)
+    visit admin_root_path
+
+    expect(page).to have_current_path(admin_root_path)
+    expect(page).not_to have_content "You do not have permission to access this page"
+  end
+
+  scenario "Admin access links" do
+    login_as(administrator)
+    visit root_path
+
+    expect(page).to have_link("Administration")
+    expect(page).to have_link("Moderation")
+    expect(page).to have_link("Valuation")
+    expect(page).to have_link("Management")
+  end
+
+  scenario "Admin dashboard" do
+    login_as(administrator)
+    visit root_path
+
+    click_link "Administration"
+
+    expect(page).to have_current_path(admin_root_path)
+    expect(page).to have_css("#admin_menu")
+    expect(page).not_to have_css("#moderation_menu")
+    expect(page).not_to have_css("#valuation_menu")
+  end
+
+  scenario "Admin menu does not hide active elements", :js do
+    login_as(administrator)
+    visit admin_budgets_path
+
+    within("#admin_menu") do
+      expect(page).to have_link "Participatory budgets"
+
+      click_link "Site content"
+
+      expect(page).to have_link "Participatory budgets"
+    end
+  end
+end